Processor-level dynamic thermal management techniques have long targeted worst-case thermal margins. We examine the thermal-performance trade-offs in average-case, preventive thermal management by actively degrading application performance to achieve long-term thermal control. We propose Dimetrodon, the use of idle cycle injection, a flexible, per-thread technique, as a preventive thermal management mechanism and demonstrate its efficiency compared to hardware techniques in a commodity operating system on real hardware under throughput and latency-sensitive real-world workloads. Compared to hardware techniques that also lack flexibility, Dimetrodon achieves favorable trade-offs for temperature reductions up to 30% due to rapid heat dissipation during short idle intervals.
